How This Deep Sea Drone Will Scan the Ocean Floor for Flight MH-370

The search for the missing Malaysia Airlines Flight 370, now in its second month, is on track to be the most expensive recovery effort in aviation history, and search crews have trotted out some of the world's most advanced technology in hopes of solving the mystery.

Today, officials launched one of the US Navy's most advanced tools, the Bluefin-21 unmanned autonomous underwater vehicle, into the southern Indian Ocean, where it will travel to the ocean floor to scan for signs of the missing jet.

The robo-sub was launched from the Australian ship Ocean Shield, kicking off the underwater phase of the search effort. After detecting four "pings" that could have come from the missing aircraft's black box, the search crew will now try to locate the source of the signals. They've narrowed down an area of the ocean floor to investigate further using the state-of-the-art drone technology.

The drone ship, under 2 feet in diameter and 16 feet long, is small and agile enough to travel nearly three miles under the surface, to an area uncharted by humans up until now. Conditions are hardly human-friendly: temps are just above freezing, it's pitch black, and the water is clouded with silt from the ocean floor.

It'll scan the area in a "lawnmower pattern"—back and forth in parallel lines, and produce a map of the area based on sound signals. The machine's side-scan sonar sensors pick up on acoustic signals as sound refracts off of objects. Then it sends out a pulse that creates a detailed 3D image of the area from the signals.

Then researchers will look for anything out of the ordinary from the imagery—unique patterns, or right angles that give a clue there's a manmade object down there. If there are any leads from the sonar scan, the sub will take a closer look with its high-res digital camera the next time around.

The autonomous ship, made by Bluefin Robotics, can last 24 hours at a time on its own, and it takes two hours just to make the trip from the surface of the sea to the bottom. The modular sub is easy to break down, so its battery is swappable in the field, making for a quick turnaround time. It's also designed to have a small turning radius, which makes it more efficient and saves time, according to the product specs. Still, it's expected to take up to two months to scan the whole area.

The robo-sub also can't transmit back data while submerged, so the information from each daily mission is downloaded after it emerges, a process that takes four hours. "This will be a slow and painstaking process," said Australian chief search coordinator Angus Houston in a news conference yesterday.

Houston also warned that the chances of the sub finding Flight 370 aren't great. But, after 38 days of searching, the black box signals are the only lead search teams have. The signal has now been silent for six days, and officials expect the black box battery, meant to last about a month, is either dead or quickly running out of juice.